Optimize timed message handling

[nordlander]

As it currently stand, it's the sender that's woken up when the timer triggers, just to place a message in the message queue of the receiver. Ideally after should result in a fully evaluated Msg that's just placed in the timer queue instead of a particular in-box because of the baseline parameter. Requires some fiddling with the type-checker, the deactorizer and the rts.